Enabling split sessions across hybrid public safety and lte networks

ABSTRACT

A special data splitter and data combiner is shown for low latency emergency and data intensive services so that multiple broadband and wireless networks can be utilized along with public safety networks. Any data session, multimedia or non-multimedia, is split into multiple packet streams with each stream having an identifier wherein some packet streams are sent via the secure public safety network and other streams are sent via other networks of varying characteristics and performance, and a combiner at the other end receiving multiple streams from different networks combines them into a single session.

RELATED APPLICATIONS

This application claims benefit of provisional application Ser. No.62/392,538 filed Jun. 6, 2016.

BACKGROUND OF THE INVENTION Field of Invention

The present invention relates to a system and method for efficientlytransporting multimedia data services over multiple telecommunicationsnetworks, such as LTE, 4G and terrestrial public safety networks bysplitting and combining data traffic according to characteristics ofmultimedia encoding methods used for video and image files anddistributing the split traffic according to the performance, resilienceand reliability of various networks. The system comprises a softwaresystem called splitter/combiner deployed on the access terminals andwithin the core network.

Discussion of Related Art

Mobile communications is a very large global industry. Revenues aloneexceed one percent of the total global GDP. Mobile operatorsparticularly in developed markets view data services as their primarysource of growth for the upcoming years. The majority of mobile datatraffic is currently served over third generation (3G) networks, usingmainly a Universal Mobile Telecommunications System (UMTS) network basedon the Global System for Mobile Communications (GSM) standards.

The increasing traffic demand is straining the capacity of 3G networksworldwide. Carriers have implemented various means to cope with thisproblem such as implementing data caps or moving to higher capacity 4Gnetworks. However, it is anticipated that, even by taking such measures,the demand for wireless data services will continue to increase rapidlyfor the foreseeable future. The migration of data services to 4Gnetworks is expected to somewhat improve the cost/revenue situation forthe delivery of broadband data services. However, the much highercapacity of “Long Term Evolution” (LTE) networks will likely give riseto higher user expectations, which in turn will likely fuel even greaterper user traffic volumes. Thus, cost effective means of maximizing theefficient usage of capacity and performance of LTE networks will be ofparticular value [see paper to Malboubi et al., “Multiple DescriptionImage Coding: A New Efficient and Low Complexity Approach for WirelessApplications,” 2005; see paper to Wang et al., “Multiple DescriptionCoding Using Pairwise Correlating Transforms,” 2001; see paper toNystrom et al., “Multiple Description Image Coding Using Regions ofInterest,” 2007].

LTE is a fourth generation (4G) wireless network technology defined bystandards issued by the Third Generation Partnership Project (3GPP).Frequency domain multiplexing provides multiple-access in LTE networks.In the downlink (or forward channel) direction the Orthogonal FrequencyDomain Multiplexing (OFDM) is used, while in the uplink channeldirection the Single Carrier Frequency Division Multiple Access(SC-FDMA) is used. LTE networks can utilize other non-3GPP or 3GPPnetworks to adjust rapid changes in demand distribution and othervariable factors. In this way, networks can maximize data throughput,speed, performance, and capacity, while maintaining required coverageand reliability.

Nowadays, efficient public safety networks are needed not only toprovide enough bandwidth when needed but also to reduce the latency inemergency conditions. For these reasons, governments, police force andorganizations involved in public safety and security are devotinginterest to transition from existing narrowband networks towardsbroadband. A prospective solution is the adaptation of LTE Advanced(4.5G) by meeting critical public safety networking requirements. Thecost, timing and spectrum availability for the deployment of publicsafety networks are fairly demanding requirements.

Current public safety networks are based on narrowband wireless systemssuch as terrestrial trunked radio (TETRA) that focus on advancedsecurity features and specific functionalities, but the support of highdata rate services that are provided by broadband commercial mobilenetworks is still lagging behind. From the communications perspective, apublic safety network is a communication network used by emergencyservices organizations, such as the police, firefighters and emergencymedical services to prevent or respond to incidents that harm orendanger persons or property. Many municipalities are turning to mobilecomputing and other networked applications to improve the efficiency oftheir workforce, including public safety personnel and first responders.Consequently, public safety workers are increasingly being equipped withwireless laptops, handheld computers, push-to-talk devices and mobilevideo cameras to improve their efficiency, visibility, and ability toinstantly collaborate with the central command, coworkers and otheragencies. Video surveillance cameras and unattended sensors are becomingmore important tools to extend the eyes and ears of public safetyagencies. The data content security in a public safety network isanother key requirement.

The U.S. based FirstNet is a typical public safety network. Usingnationwide 700 MHz spectrum, FirstNet aims at putting an end todecades-long interoperability and communications challenges and helpkeep the US communities and emergency responders safer. US Congressallocated valuable spectrum and up to $7 billion in funding for theconstruction of the FirstNet network. To create a nationwide network,all 56 U.S. states and territories are provided with a radio accessnetwork that is connected to the FirstNet core network. To containcosts, FirstNet is tasked with leveraging existing telecommunicationsinfrastructure and assets. This includes exploring public/privatepartnerships that can help support and accelerate the creation of thisnew advanced wireless network.

The need to access and share the vital new flow of data, voice, videoand images is driving investments in a new kind of network: a broadbandwireless mesh network based public safety network using WiMAX, and LTE,or a combination. These networks are metropolitan or regional in scope,can maintain connections with highly mobile workers, deliver largeamounts of low-cost bandwidth with extremely high reliability, andsupport real-time video, voice and data. Several networking alternativesare being evaluated:

-   -   Modern Dedicated Public Safety network infrastructure.    -   Public Safety network over broadband commercial networks.    -   Hybrid solutions.

Dedicated networks have lower cost, rapid deployment and can be kept asstate of the art. However, they may experience possible coverage holesand lack of features and redundancy. Also, traffic congestion andnetwork downtime could be experienced. The usage of commercial networks,on the other hand, provides required resiliency, coverage, redundancyand higher availability. It has guaranteed QoS and full support formission critical applications. While they have flexible coverage, thenetwork cost will be higher and service deployment time will be longer.Hybrid solutions are the best of both worlds, but they require resourcesharing policies and additional network infrastructure components whenthere are coverage holes. As a result, usage of various networks is anecessity and part of the 5G heterogeneous networking. The method andsystem presented here applies to a hybrid solution case, and furtherincreases the granularity and efficiency of usage when there are atleast two networks used for the transport of the same data session.

Embodiments of the present invention are an improvement over prior artsystems and methods.

SUMMARY OF THE INVENTION

In one embodiment, the present invention provides a user terminaloperable in a first wireless network and a second wireless network(e.g., the first wireless network may be a dedicated public safetynetwork and the second wireless network may be a commercial wirelessbroadband network), the user terminal comprising: (a) a processor; (b) astorage; (c) a first network interface to communicate with the firstwireless network; (d) a second network interface to communicate with thesecond wireless network; (e) the processor executing instructions in thestorage to implement a resident umbrella layer, the resident umbrellalayer measuring in real-time network capabilities associated with thetwo wireless networks via the first and second network interface,respectively, and (f) the processor executing instructions in thestorage to implement a splitter to split each outgoing packet streamoriginated from the user terminal into at least two separate streamsaccording to the measured network capabilities in (e), wherein the firstnetwork interface sends one stream to a first network base stationassociated with the first wireless network, and the second networkinterface sends another stream to a second network base stationassociated with the second wireless network. In an extended embodiment,the user terminal further implements a combiner to receive separatepacket streams from the first and second base stations and combine theminto a single stream, the single stream originating from another userterminal.

In another embodiment, the present invention provides a core networkgateway comprising: (a) a processor; (b) a storage; (c) a first networkinterface to communicate with a first core network; (d) a second networkinterface to communicate with a second core network; (e) the processorexecuting instructions in the storage to implement a combiner: (1)receiving a first stream from the first core network over the firstnetwork interface receiving a second stream from the second core networkover the second network interface, the first and second streamoriginating from a first user terminal, and (2) combining the first andsecond stream into a single stream for forwarding to a second userterminal. In an extended embodiment, the core network gateway furtherimplements a splitter to receive a packet stream from the second userterminal and splitting it into a third and fourth stream for forwardingover the first and second network interface, respectively, to the firstuser terminal capable of receiving split packet streams.

In yet another embodiment, the present invention provides a system forcommunicating over at least a first wireless network and second wirelessnetwork, the first wireless network being a wireless dedicated publicsafety network and the second wireless network being a commercialwireless broadband network, the first wireless network associated withat least a first base station and the second wireless network associatedwith at least a second base station, the system comprises: (a) at leasta first user terminal attached to the first and second base stations,the user terminal comprising: (1) a first network interface tocommunicate with the first wireless network and a second networkinterface to communicate with the second wireless network; (2) aresident umbrella layer measuring in real-time network capabilitiesassociated with the first and second wireless networks using the firstand second network interfaces, respectively, and (3) a splitterfunctionality to split each outgoing packet stream originated from thefirst user terminal into at least two separate streams according to themeasured network capabilities, where the first and second networkinterfaces sending one stream to the first base station and the otherstream to the second base station, (b) at least a second user terminalattached only to the first base station of the public safety network,and (c) a core network gateway comprising: (1) two network interfacesreceiving one packet stream from a first core network and another packetstream from a second core network, and (2) a combiner functionality toreceive the two packet streams from both core networks and combine theminto a single stream generating the outgoing packet stream originatedfrom the first terminal, and sending the combined stream to the seconduser terminal over the public safety network.

In yet another embodiment, the present invention provides a system forcommunicating over at least a first wireless network and second wirelessnetwork, the first wireless network being a wireless dedicated publicsafety network and the second wireless network being a commercialwireless broadband network, the first wireless network associated withat least a first base station and the second wireless network associatedwith at least a second base station, the system comprises: (a) at leasta first user terminal attached to base station of said public safetynetwork originating a data stream, (b) a core network gateway having aconnection to core networks of both first and second networks, and asplitter functionality receiving the data stream from said first userterminal and split it into two streams according to capabilities of thefirst and second wireless networks, and (c) at least a second userterminal attached to base stations of the first and second networksreceiving the two streams from the base stations having a combinerfunctionality to combine the two packet streams coming from the corenetwork gateway into the originated data stream by the first userterminal.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure, in accordance with one or more various examples,is described in detail with reference to the following figures. Thedrawings are provided for purposes of illustration only and merelydepict examples of the disclosure. These drawings are provided tofacilitate the reader's understanding of the disclosure and should notbe considered limiting of the breadth, scope, or applicability of thedisclosure. It should be noted that for clarity and ease of illustrationthese drawings are not necessarily made to scale.

FIG. 1 illustrates a high level network diagram showing components ofthis invention.

FIG. 2 describes the ATSP methods of combining and splitting.

FIG. 3 illustrates a high-level block diagram of the splitter of theATSP.

FIG. 4 illustrates a high-level block diagram of the combiner of theATSP.

FIG. 5 illustrates a high-level network diagram with access terminalsand CNCP.

FIG. 6 illustrates a high-level block diagram on CNCP.

FIG. 7 illustrates a flow chart showing the splitting method within anATSP.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

While this invention is illustrated and described in a preferredembodiment, the invention may be produced in many differentconfigurations. There is depicted in the drawings, and will herein bedescribed in detail, a preferred embodiment of the invention, with theunderstanding that the present disclosure is to be considered as anexemplification of the principles of the invention and the associatedfunctional specifications for its construction and is not intended tolimit the invention to the embodiment illustrated. Those skilled in theart will envision many other possible variations within the scope of thepresent invention.

Note that in this description, references to “one embodiment” or “anembodiment” mean that the feature being referred to is included in atleast one embodiment of the invention. Further, separate references to“one embodiment” in this description do not necessarily refer to thesame embodiment; however, neither are such embodiments mutuallyexclusive, unless so stated and except as will be readily apparent tothose of ordinary skill in the art. Thus, the present invention caninclude any variety of combinations and/or integrations of theembodiments described herein.

An electronic device (e.g., a base station, gateway, switch, or userterminal) stores and transmits (internally and/or with other electronicdevices over a network) code (composed of software instructions) anddata using machine-readable media, such as non-transitorymachine-readable media (e.g., machine-readable storage media such asmagnetic disks; optical disks; read only memory; flash memory devices;phase change memory) and transitory machine-readable transmission media(e.g., electrical, optical, acoustical or other form of propagatedsignals—such as carrier waves, infrared signals). In addition, suchelectronic devices include hardware, such as a set of one or moreprocessors coupled to one or more other components—e.g., one or morenon-transitory machine-readable storage media (to store code and/ordata) and network connections (to transmit code and/or data usingpropagating signals), as well as user input/output devices (e.g., akeyboard, a touchscreen, and/or a display) in some cases. The couplingof the set of processors and other components is typically through oneor more interconnects within the electronic devices (e.g., busses andpossibly bridges). Thus, a non-transitory machine-readable medium of agiven electronic device typically stores instructions for execution onone or more processors of that electronic device. One or more parts ofan embodiment of the invention may be implemented using differentcombinations of software, firmware, and/or hardware.

As used herein, a network device such as a base station, a router, agateway, a splitter/combiner per this invention are networkingcomponents including hardware and software that communicativelyinterconnect with other equipment of the network (e.g., other networkdevices, and end systems). Base stations provide the function of accessdata transmission over wireless (radio) links for wireless terminalssuch as telephones, computers, Internet of Things (IoT), etc., andprovide the core network connectivity to other networking equipment suchas gateways, routers and switches that exhibit multiple layer networkingfunctions (e.g., routing, bridging, switching, Quality of Service,and/or subscriber and roaming management), and/or provide support fortraffic coming from multiple application services (e.g., data, voice,and video).

Note while the illustrated examples in the specification discuss mainlyvideo coded according to multi description coding (MDC), which is acoding technique that separates a digital video data stream intomultiple data streams, each with a so called “different description”,other coding methods that generate multiple digital data streams such asscalable video coding (SVC), or techniques according to H.264 and H.265MPEG standards and even newer standards are equally applicable. Withscalable video coding, a base layer and multiple enhancement layers ofthe video are generated as separate streams, and when combined they formthe video. The base layer (crucial information) provides a minimalrepresentation of the video while with each added enhancement layer(optional information) the video resolution is improved. However, anenhancement layer cannot be used to construct the image without the baselayer. This type of decomposition provides an added security when thebase layer is sent via a secure network such as the public safetynetwork while only the enhancement layers are sent on commercialnetworks. Unless specified otherwise, the embodiments of the inventionapply to any such encoded multimedia stream that can be separated intomultiple streams wherein one of the stream components (a description ora base layer) can generate a meaningful enough representation of thedata while additional stream components (additional descriptions orenhancement layers) when superimposed enhance the quality of thereceived multimedia data (e.g., video resolution). Such methods areavailable for jpeg-encoded images as well. The methods equally apply tounicast, multicast and broadcast type services. In what follows, hybridnetwork examples are shown with two networks only, while we should notethat more than two networks are also viable.

The present invention is designed to solve the above-mentioned problemsin a multiple access network setting. The proposed system has an AccessTerminal Combiner & SPlitter (ATSP) implemented at the user terminalsuch as a wireless telephone or a wireless laptop and a Core NetworkCombiner & SPlitter (CNCP) implemented in a gateway in the core of thenetwork. In the access network, there are a plurality of Base Stationsof various different networks like a commercial public LTE network and adedicated public safety network.

ATSP is a software that resides in the access terminal network stackwithin the Operating System (OS), and CNCP is a gateway (both hardwareand software) located somewhere in the north of the core network. Theremay be at least one CNCP in the network. Both ATSP and CNCP have areciprocal combiner and splitter mechanisms. Being a network component,CNCP may have an internal routing functionality as well. When ATSPdivides up a data session into multiple sessions and distributes overmultiple networks, CNCP performs the combining function if the sessionsare coming from different base stations (i.e., the uplink direction).Alternatively, the CNCP can perform the splitting towards multiplenetworks' base stations (i.e., the downlink direction) in which caseATSP performs the combining function.

The base stations have wired and wireless interfaces. The wiredinterface is to connect the base station to the core data network. Thewireless interface is to connect to the user terminals. Each basestation has a fixed amount of wireless resource blocks and is requiredto fairly distribute this resource to all of the user terminalsreceiving service from that base station. It is envisioned that theoffered services according to this patent will support a set ofheterogeneous user terminals and networks.

As for prior art, US 20120147860 sends multiple versions of a multimediapacket to the base station, and, based on the radio channel and trafficcharacteristics, an appropriate version of the multimedia packet is sentto the destination mobile station at a given time. In this way, sourcetransmission is improved according to instantaneous network conditions.This invention focuses on reliability rather than efficiency and lowlatency.

US 20120314948 utilizes the multi-description coding (MDC) formultimedia content with a plurality of forms of diversity. Based onmotion or any other metric of interest, they fragment a source into oneor more region of interest (ROI) portions and non-ROI portions. One ormore of these portions can further be fragmented by sub-sampling therespective portions to generate a plurality of lower-resolutionversions, e.g., with alternating groups of pixels in respectiveversions. Still further, one or more of these portions can be furtherfragmented by image frames, etc. with alternating frames in respectivefragments. At least one ROI portion and lower-resolution versions maythen be encoded into a plurality of descriptions and transmitted.Utilizing various combinations of ROI diversity, resolution diversity,and frame rate diversity, channel utilization and robustness forstreaming multimedia content can be improved. This invention mainlyclaims better diversity by leveraging MDC.

US 20130051321 presents a disclosure that includes a wireless system toreduce quantization error due to codebook-based pre-coding matrixindicators (PMI) reported by pre-coding channel state informationreference signals (CSI-RSs) via a base station. The base station variesthe properties for a CSI-RS transmission in a known pattern and receivesvarying reports from the user terminal. The base station can reconstructthe PMI with improved accuracy by combining multiple consecutivedescriptions. The invention mainly uses MDC for coding information.

A high-level network diagram with the systems of the invention isillustrated in FIG. 1. In a simple exemplary scenario, a mobile UserTerminal 101, which is a video camera, sends a video recording to videodatabase server 112. First, the video is encoded as two streams using anMDC or SVC video encoder, which is illustrated as application 101 d.ATSP 101 a resides in the User Terminal and separates these two streamsand sends them towards the two network interfaces. One stream is senttowards base station 103 a and the rest of the stream is sent towardsbase station 104 a, via network interfaces 101 c and 101 d,respectively. Any data stream originated from 101 and sent to Basestation 103 a is routed towards CNCP 102 in the core of public safetynetwork 103, and similarly base station 104 a of the commercial LTEnetwork sends the data stream it receives from user terminal 101 towardsCNCP 102, attached to commercial LTE core network 104 according to anaspect of this invention. Commercial LTE network routers are configuredwith routing table entries such that packets originating from those userterminals of the public safety network are always forwarded towards thenearest CNCP 102 to the destination, which is attached to both networksand combines the streams received from different networks. CNCP 102routes the video stream assembled from the two streams to video database112 attached to a public safety data center 117.

The ATSP and CNCP have both the combiner and splitter functionalities,meaning, when ATSP is splitting, CNCP is combining, and when CNCP issplitting, ATSP is combining. In the exemplary scenario of FIG. 1, theATSP is in a splitting role while the CNCP is in a combining role.

FIG. 2 shows the mobile user terminal 101 in which the ATSP function isdeployed. Example application 201 on the user terminal is a videoencoder/decoder. ATSP is further blown up to show splitting function203, and its dual, combining function 202. Depending on the direction oftraffic (uplink or downlink) one of these functions is selected.Splitting 203 is selected if the traffic origination is the sourceapplication 201 (i.e., the application is in encoding mode) and thetraffic is outgoing. The traffic is split into two (or more), and sentto network interfaces 205 and 204, respectively. The ATSP acts ascombiner 202 for the incoming video traffic from network interfaces 204and 205 when application 201 is the destination (i.e., the applicationis in decoding mode). The arrows are used to illustrate the direction oftraffic.

ATSP:

FIG. 3 illustrates Splitter 203 sub-function of ATSP shown in FIG. 2 inmore detail. The splitter at the user terminal performs multimediasplitting, wherein the session has multimedia content such as video orimage that may be further processed for splitting across multiplenetworks. For non-multimedia data, splitter provides a packet level datasplitting. Note that audio is not split, as it is already narrowbandtherefore does not require any further processing to distribute acrossmultiple networks unless there are security reasons to do so.

Umbrella Layer 303:

When a multimedia data session is started, application 201 sends thisrequest to Umbrella Layer (UL) 303, which is resident in the userterminal and continuously monitors the wireless transport capabilitiesof its network connections via the TETRA and LTE networks by monitoringdata traffic passing across Network Interfaces 101 c and 101 d,respectively. Umbrella Layer 303, for example, gathers statistics interms of packet latency, packet loss and bandwidth on each networkinterface. This layer is required to handle applications that createsessions with different transport requirements, and dispatch traffic todifferent network interfaces. For instance, applications that requireimmediate image or video transmission have a different process thanapplications that send bulky data. The goal is to save time in gettingcritical multimedia information in the hands of first responders byleveraging parallel networks.

Image Splitter 309:

Image splitter 309 is attached to Image Codec 216 b, which performs JPEGencoding of images. If the image is large and must be transmitted overboth networks interfaces, which is determined by Umbrella Layer 303,then it has to be encoded accordingly. The image can be encoded withdecimated versions using a JPEG coder with N/2 point Discrete CosineTransform (DCT) so that two descriptions of the encoded image aregenerated; thereby, allowing transmission over two separate channels.When both descriptions exist, a high quality image can be reconstructed.On the other hand, if only the first description exists, it hasacceptable quality. This encoder system does not introduce any extrawork and the correlation between descriptions comes from the intrinsiccorrelation of spatial pixels. Another possibility is to perform JPEGtransformation more than twice to send over the two interfaces. The maindescription is sent through LTE and other descriptions, which requiremuch less bandwidth, are sent through TETRA. This way, image quality canbe increased over time as more descriptions arrive at the destination.Such encoding techniques are prior art as current networks are able tosend high quality images by leveraging different networks.

Video Splitter 307:

Video Splitter 307 is attached to Video Codec 216 a which uses multipledescription coding (DCT) and/or scalable video coding (SVC) techniquesand/or other similar coding methods. There are methods that do simplerate splitting or methods that calculate two simple parameters tocharacterize the smoothness and edge features of each block of an MPEGvideo frame. These two parameters are used as a measure of theperceptual tolerance of DCT blocks against visual distortion. Theyduplicate the key information such as motion vectors and somelow-frequency DCT coefficients, and split the remaining DCT coefficientsof prediction errors according to the calculated perceptual toleranceparameter. These are handled by our multiple description transmissionsystem for MPEG video frames as well.

Umbrella Layer 303 communicates with the video encoder 216 a toimplement rate splitting as the default method when capacity, jitter andlatency are adequate for both connections to transport descriptions (orlayers) of the video. Video Splitter 307, in turn, bundles one or moreof the descriptions (depending on the bandwidth available at eachnetwork connection) and sends them toward one of the Network Interfacesas illustrated in the figure. An added benefit of using SVC as opposedto MDC is the extra security. If the SVC base layer, which requires alow bandwidth, is transported over the secure TETRA network, theenhancement layers can be sent over a commercial public LTE network.However, one cannot recreate the video simply by capturing theenhancement layers, i.e., without using the base layer. Best features ofthe coding techniques can be utilized on a case-by-case basis.

Data Splitter 305:

When there is a non-multimedia data stream, Data Splitter 305 performsan optimized packet level splitting in order to utilize the best of bothchannels. From Umbrella Layer 303, Data Splitter 305 receives thenecessary capacity and latency information from each network interfaceand splits the packets according to the received information. Hence,towards one network interface, a packet can have a different size andtiming than another network interface. For instance, if one of thewireless network interfaces is TETRA, which is narrowband, supportedpacket size is smaller with reduced time interval between packetswherein LTE packets can be much larger. Accordingly, the Splitterperforms a real-time statistical splitting to adaptively chop thepackets to comply with different characteristics of various networkinterfaces collected by Umbrella Layer 303. If in certain cases, therecould be a broadcast message that is originated in an access terminal tobe distributed to all other access terminals. The data splitter utilizesboth network interfaces to produce a broadcast message. It replicatespackets with different packet sizes according to the information itreceives from Umbrella Layer 303. Other mobile terminals receiving itfrom their dual interfaces reconstruct the information through theCombiner.

FIG. 4 illustrates Combiner 202 functionality of ATSP. It is essentiallythe reciprocal of the Splitting 203 functionality. The Combiner bringsthe packets into order based on packet headers. If any packet ismissing, it initiates the recovery mechanism using TCP, RTP, RTCP, etc.In some cases, it may elect to transmit an erroneous packet to thedestination to let destination ignite a retransmission.

In order to further clarify the division of splitting/combining tasksbetween the ATSP and CNCP, FIG. 5 illustrates a high-level examplenetwork diagram with Access Terminals A, B and C and database server112, all attached to public safety network 103. These access terminalscan be wireless laptops, wireless telephones, wireless sensors, etc.Note that Access Terminals B and C are attached to Base Station X,Access Terminal A is attached to Base Station Y, and DB Server 112 isattached to the core public safety network. The DB server is possibly arepository of all images and videos taken by access terminals andlocated in a secure data center attached to the core of public safetynetwork 103. In a hybrid networking configuration, Access Terminals Aand B are also attached to LTE network 104 via LTE base station Z, andtherefore have ATSP functions for content splitting/combining at theaccess terminal. CNCP 102 is attached to core public safety network 103and core LTE network 104.

If an access terminal or server is only attached to the public safetynetwork, then the splitting function must be performed by the nearestCNCP within the core network. If an access terminal or server isattached to both networks, however, the splitting function is performedby the ASTP on the access side. The splitting and combining functionsare therefore performed by the ATSP or the CNCP depending on thecapabilities of the access terminal originating or terminating contentas illustrated for various originating (from)-terminating (to) scenariosthat correspond to the network configuration of FIG. 5:

TABLE 1 Splitting Combining From To Function Function Access Access ATSPA ATSP B Terminal A Terminal B Access Access ATSP A CNCP Terminal ATerminal C Access DB Server ATSP A CNCP Terminal A 112 Access AccessCNCP ATSP A Terminal C Terminal A DB Server 112 Access — — Terminal C

In summary, if the destination of a content originated from an accessterminal hosting an ATSP that is simultaneously attached to the publicsafety network and the LTE network, and if the destination host is alsosimultaneously attached to the public safety network and the LTEnetwork, then the combining function for the content can be performed bythe destination's Combining Function 202 as illustrated in FIG. 4.However, if the destination host is attached only to the public safetynetwork, then the combining must be performed within the core network bythe CNCP right before sending the content to the destination. Similarly,if the content is originating from a host that is attached only to thepublic safety network, then at the core network, the CNCP can performthe splitting of the content so that it can be transmitted over twonetworks toward the destination access terminal that has attachment toboth networks.

A high-level block diagram of the CNCP is shown in FIG. 6. CNCP isattached to the core of TETRA and LTE networks with Network Interfaces511 and 510, respectively. Splitter 570 and Combiner 571 performsplitting and combining of video, image and other data traffic accordingto an aspect of this invention, as described in detail in the ATSPsystem. Umbrella Layer 552 gathers network related performanceinformation from network interfaces 511 and 510 just as in the ATSPsystem. This information is used to determine how to dispatch split datastreams onto different networks.

CNCP has AT Registry database 542 which keeps the information of allAccess Terminals (such as IP addresses and MAC addresses) of the publicsafety network components, and if they have the ATSP function or not.The key function of the CNCP is Packet Processing Engine 532, whichforwards each data packet to either Combiner 571 or Splitter 570 bysimply inspecting the origination and destination IP addresses andchecking them against a Routing Table that has proper forwardinginstructions for data coming from or going to each Access Terminal thatare at the AT Registry. For example, if a data packet is received fromNI 511 originated from IP address of Access Terminal A and destined toIP address of Access Terminal C of FIG. 5, Packet Processing Engine 532looks up its forwarding table and notices that AT A sends split data(because it has a resident ATSP function) but AT C has no combiningfunction (because it is connected to public safety network only). Thus,it has an instruction to forward any packet from AT A towards Combiner571, which in turn inspects the packet header information to identify ifit is a video, image or data packet and identify which sub-function ofCombiner 571 to send it to for combining. Combined data packets from ATA towards AT C are then routed back to the proper Network Interface viaRouting Engine 522, which has the Routing Table for outgoing traffic.The CNCP optionally has Policy Engine 512, which contains rules for dataprocessing priorities and policies for certain data streams. Thesepolicies feed into Packet Processing Engine 532. If the destination isanother AT with ATSP function, then CNCP simply transmits the datapacket as is to destination ATSP.

FIG. 7 illustrates a high-level flow-chart of the splitting methodwithin an ATSP or a CNCP. The process starts at step 601 when theapplication (local if it is an ATSP or remote if it is a CNCP) startsgenerating stream of packets. In step 602, the system checks todetermine if the stream of packets is multimedia or not. If theapplication generates non-multimedia packets, the data is sent to datasplitter in step 614. If the application generates multimedia data, thesystem checks to determine if the data is image or video in step 603. Ifthe data is an image, then in step 605, the system sends the data to theJPEG codec to encode a split image according to an aspect of thisinvention. If the data is a video, then in step 615 the system sends thedata to MDC/SVC codec to encode the video in split streams. Meanwhile,Umbrella Layer has been monitoring the capabilities of both TETRA andLTE networks simply by collecting data from the network interfaces instep 651. Capabilities, such as packet latency, BW and packet loss rateare processed and fed to the Splitters 614, 609 and 607. Subsequently,these splitters split and then bundle sessions according to thecapabilities of the networks, and generate the sessions in step 621ready for sending to the network interfaces. In step 631, the sessionsare sent to the network interfaces and to the associated networks fortransport.

Multimedia session splitting can be accomplished by decomposing filesinto crucial and less crucial parts such that crucial and vital datastreams are sent to the public safety network, while other non-crucialstreams are sent to non-safe networks and cannot be used without thevital blocks to reconstruct the multimedia content, thereby attaininghigh data security. The vital parts are sent over a low latency andhighly reliable safe network and less crucial parts are sent over one ormore high capacity but not highly reliable networks. The splitting isadaptable and can change over time according to topology and networkconditions. Other embodiments of the splitting method of this inventionare specifically for the uplink only or the downlink only using a corenetwork based splitter and combiner, or for broadcast typecommunications flooded over the public safety network.

Many of the above-described features and applications can be implementedas software processes that are specified as a set of instructionsrecorded on a computer readable storage medium (also referred to ascomputer readable medium). When these instructions are executed by oneor more processing unit(s) (e.g., one or more processors, cores ofprocessors, or other processing units), they cause the processingunit(s) to perform the actions indicated in the instructions.Embodiments within the scope of the present disclosure may also includetangible and/or non-transitory computer-readable storage media forcarrying or having computer-executable instructions or data structuresstored thereon. Such non-transitory computer-readable storage media canbe any available media that can be accessed by a general purpose orspecial purpose computer, including the functional design of any specialpurpose processor. By way of example, and not limitation, suchnon-transitory computer-readable media can include flash memory, RAM,ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storageor other magnetic storage devices, or any other medium which can be usedto carry or store desired program code means in the form ofcomputer-executable instructions, data structures, or processor chipdesign. The computer readable media does not include carrier waves andelectronic signals passing wirelessly or over wired connections.

Computer-executable instructions include, for example, instructions anddata which cause a general purpose computer, special purpose computer,or special purpose processing device to perform a certain function orgroup of functions. Computer-executable instructions also includeprogram modules that are executed by computers in stand-alone or networkenvironments. Generally, program modules include routines, programs,components, data structures, objects, and the functions inherent in thedesign of special-purpose processors, etc. that perform particular tasksor implement particular abstract data types. Computer-executableinstructions, associated data structures, and program modules representexamples of the program code means for executing steps of the methodsdisclosed herein. The particular sequence of such executableinstructions or associated data structures represents examples ofcorresponding acts for implementing the functions described in suchsteps.

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read-only memory ora random access memory or both. The essential elements of a computer area processor for performing or executing instructions and one or morememory devices for storing instructions and data. Generally, a computerwill also include, or be operatively coupled to receive data from ortransfer data to, or both, one or more mass storage devices for storingdata, e.g., magnetic, magneto-optical disks, or optical disks. However,a computer need not have such devices. Moreover, a computer can beembedded in another device, e.g., a mobile telephone, a personal digitalassistant (PDA), a mobile audio or video player, a game console, aGlobal Positioning System (GPS) receiver, or a portable storage device(e.g., a universal serial bus (USB) flash drive), to name just a few.

In this specification, the term “software” is meant to include firmwareresiding in read-only memory or applications stored in magnetic storageor flash storage, for example, a solid-state drive, which can be readinto memory for processing by a processor. Also, in someimplementations, multiple software technologies can be implemented assub-parts of a larger program while remaining distinct softwaretechnologies. In some implementations, multiple software technologiescan also be implemented as separate programs. Finally, any combinationof separate programs that together implement a software technologydescribed here is within the scope of the subject technology. In someimplementations, the software programs, when installed to operate on oneor more electronic systems, define one or more specific machineimplementations that execute and perform the operations of the softwareprograms.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, declarative orprocedural languages, and it can be deployed in any form, including as astand-alone program or as a module, component, subroutine, object, orother unit suitable for use in a computing environment. A computerprogram may, but need not, correspond to a file in a file system. Aprogram can be stored in a portion of a file that holds other programsor data (e.g., one or more scripts stored in a markup languagedocument), in a single file dedicated to the program in question, or inmultiple coordinated files (e.g., files that store one or more modules,sub programs, or portions of code). A computer program can be deployedto be executed on one computer or on multiple computers that are locatedat one site or distributed across multiple sites and interconnected by acommunication network.

These functions described above can be implemented in digital electroniccircuitry, in computer software, firmware or hardware. The techniquescan be implemented using one or more computer program products.Programmable processors and computers can be included in or packaged asmobile devices. The processes and logic flows can be performed by one ormore programmable processors and by one or more programmable logiccircuitry. General and special purpose computing devices and storagedevices can be interconnected through communication networks.

Some implementations include electronic components, for examplemicroprocessors, storage and memory that store computer programinstructions in a machine-readable or computer-readable medium(alternatively referred to as computer-readable storage media,machine-readable media, or machine-readable storage media). Someexamples of such computer-readable media include RAM, ROM, read-onlycompact discs (CD-ROM), recordable compact discs (CD-R), rewritablecompact discs (CD-RW), read-only digital versatile discs (e.g., DVD-ROM,dual-layer DVD-ROM), a variety of recordable/rewritable DVDs (e.g.,DVD-RAM, DVD-RW, DVD+RW, etc.), flash memory (e.g., SD cards, mini-SDcards, micro-SD cards, etc.), magnetic or solid state hard drives,read-only and recordable Blu-Ray® discs, ultra density optical discs,any other optical or magnetic media, and floppy disks. Thecomputer-readable media can store a computer program that is executableby at least one processing unit and includes sets of instructions forperforming various operations. Examples of computer programs or computercode include machine code, for example is produced by a compiler, andfiles including higher-level code that are executed by a computer, anelectronic component, or a microprocessor using an interpreter.

While the above discussion primarily refers to microprocessor ormulti-core processors that execute software, some implementations areperformed by one or more integrated circuits, for example applicationspecific integrated circuits (ASICs) or field programmable gate arrays(FPGAs). In some implementations, such integrated circuits executeinstructions that are stored on the circuit itself.

As used in this specification and any claims of this application, theterms “computer readable medium” and “computer readable media” areentirely restricted to tangible, physical objects that store informationin a form that is readable by a computer. These terms exclude anywireless signals, wired download signals, and any other ephemeralsignals.

CONCLUSION

A system and method has been shown in the above embodiments for theeffective implementation of enabling split sessions across hybrid publicsafety and LTE networks. While various preferred embodiments have beenshown and described, it will be understood that there is no intent tolimit the invention by such disclosure, but rather, it is intended tocover all modifications falling within the spirit and scope of theinvention, as defined in the appended claims. For example, the presentinvention should not be limited by software/program, computingenvironment, or specific computing hardware.

1. A user terminal operable in a first wireless network and a secondwireless network, the user terminal comprising: a. a processor; b. astorage; c. a first network interface to communicate with the firstwireless network; d. a second network interface to communicate with thesecond wireless network; e. the processor executing instructions in thestorage to implement a resident umbrella layer, the resident umbrellalayer measuring in real-time network capabilities associated with thetwo wireless networks via the first and second network interface,respectively, and f. the processor executing instructions in the storageto implement a splitter to split each outgoing packet stream originatedfrom the user terminal into at least two separate streams according tothe measured network capabilities in (e), wherein the first networkinterface sends one stream to a first network base station associatedwith the first wireless network, and the second network interface sendsanother stream to a second network base station associated with thesecond wireless network.
 2. The user terminal of claim 1, furthercomprising the processor executing instructions in the storage toimplement a combiner to receive separate packet streams from the firstand second base stations and combine them into a single stream, thesingle stream originating from another user terminal.
 3. The userterminal of claim 1, wherein the first wireless network is a dedicatedpublic safety network and the second wireless network is a commercialwireless broadband network.
 4. The user terminal of claim 3, wherein thetwo separate streams comprise a first crucial data stream and a secondnon-crucial data stream, wherein the outgoing packet stream cannot bereconstructed without the first crucial data stream, and wherein thecrucial data is routed towards the dedicated public safety network. 5.The user terminal of claim 1, wherein the outgoing packet streamcomprises any of the following: multimedia stream, non-multimediastream, unicast stream, or broadcast stream.
 6. The user terminal ofclaim 1, wherein the splitter comprises a plurality of splitters forsplitting different stream types, the plurality of splitters comprisingany of the following: a data splitter, a video splitter, or an imagesplitter.
 7. The user terminal of claim 6, wherein the image splitteruses JPEG transformation to obtain multiple descriptions.
 8. The userterminal of claim 6, wherein the video splitter uses multiple streamsgenerated by any of the following coding methods: multi descriptioncoding, scalable video coding, or H.265 video coding.
 9. The userterminal of claim 6, wherein the data splitter uses adjusted packetsizes and timing for each split packet stream according to availablenetwork bandwidth.
 10. The user terminal of claim 1, wherein themeasured capabilities are any of, or a combination of, the following:packet latency, packet jitter, packet loss, or bit rate of the wirelessinterfaces.
 11. The user terminal of claim 1, wherein the user terminalis fortified with retransmission mechanisms for missing or erroneouspackets.
 12. A core network gateway comprising: a. a processor; b. astorage; c. a first network interface to communicate with a first corenetwork; d. a second network interface to communicate with a second corenetwork; e. the processor executing instructions in the storage toimplement a combiner: i. receiving a first stream from the first corenetwork over the first network interface receiving a second stream fromthe second core network over the second network interface, the first andsecond stream originating from a first user terminal, and ii. combiningthe first and second stream into a single stream for forwarding to asecond user terminal.
 13. The core network gateway of claim 12, furthercomprising the processor executing instructions in the storage toimplement a splitter to receive a packet stream from the second userterminal and splitting it into a third and fourth stream for forwardingover the first and second network interface, respectively, to the firstuser terminal capable of receiving split packet streams.
 14. The corenetwork gateway of claim 12, wherein the first core network is adedicated public safety network and the second core network is acommercial wireless broadband network.
 15. The core network gateway ofclaim 14, wherein the first stream comprises a first crucial data streamand the second stream comprises a second non-crucial data stream,wherein the combining step is not possible without the first crucialdata stream, and wherein the crucial data is routed towards thededicated public safety network.
 16. The core network gateway of claim12, wherein the single stream comprises any of the following: multimediastream, non-multimedia stream, unicast stream, or broadcast stream. 17.The core network gateway of claim 12, wherein the combiner comprises aplurality of combiners for combining different stream types, theplurality of combiners comprising any of the following: a data combiner,a video combiner, or an image combiner.
 18. The core network gateway ofclaim 17, wherein the image combiner uses JPEG transformation to obtainmultiple descriptions.
 19. The core network gateway of claim 17, whereinthe video combiner uses multiple streams generated by any of thefollowing coding methods: multi description coding, scalable videocoding, or H.265 video coding.
 20. The core network gateway of claim 17,wherein the data combiner uses adjusted packet sizes and timing for eachsplit packet stream according to available network bandwidth.
 21. Asystem for communicating over at least a first wireless network andsecond wireless network, the first wireless network being a wirelessdedicated public safety network and the second wireless network being acommercial wireless broadband network, the first wireless networkassociated with at least a first base station and the second wirelessnetwork associated with at least a second base station, the systemcomprises: a. at least a first user terminal attached to the first andsecond base stations, the user terminal comprising: i. a first networkinterface to communicate with the first wireless network and a secondnetwork interface to communicate with the second wireless network; ii. aresident umbrella layer measuring in real-time network capabilitiesassociated with the first and second wireless networks using the firstand second network interfaces, respectively, and iii. a splitterfunctionality to split each outgoing packet stream originated from thefirst user terminal into at least two separate streams according to themeasured network capabilities, where the first and second networkinterfaces sending one stream to the first base station and the otherstream to the second base station, b. at least a second user terminalattached only to the first base station of the public safety network,and c. a core network gateway comprising: i. two network interfacesreceiving one packet stream from a first core network and another packetstream from a second core network, and ii. a combiner functionality toreceive the two packet streams from both core networks and combine theminto a single stream generating the outgoing packet stream originatedfrom the first terminal, and sending the combined stream to the seconduser terminal over the public safety network.
 22. A system forcommunicating over at least a first wireless network and second wirelessnetwork, the first wireless network being a wireless dedicated publicsafety network and the second wireless network being a commercialwireless broadband network, the first wireless network associated withat least a first base station and the second wireless network associatedwith at least a second base station, the system comprises: a. at least afirst user terminal attached to base station of said public safetynetwork originating a data stream, b. a core network gateway having aconnection to core networks of both first and second networks, and asplitter functionality receiving the data stream from said first userterminal and split it into two streams according to capabilities of thefirst and second wireless networks, and c. at least a second userterminal attached to base stations of the first and second networksreceiving the two streams from the base stations having a combinerfunctionality to combine the two packet streams coming from the corenetwork gateway into the originated data stream by the first userterminal.